Consideration of the results of the interaction of electromagnetic radiation with non-spherical atmospheric particles with anisotropic properties is of both scientific and practical interest. Particular attention should be paid to the interaction of directed optical radiation with spatially oriented atmospheric ice crystals. Failure to take into account the mirror image of optical radiation from an ensemble of spatially oriented atmospheric particles of non-spherical shape can distort model representations, significantly complicate the interpretation of the results obtained and lead to incorrect interpretation of some phenomena observed in the atmosphere. The paper considers some results of observations of the phenomenon of mirror reflection from horizontally-oriented flat crystal parts localized in the atmosphere. This study was supported by the Ministry of Science and Higher Education of the Russian Federation.
The article presents an overview of the panoramic optical station "TomSky" developed at the IOA SB RAS, designed for day and night multiparametric observation of the optical state of the sky. In the second part, methods and algorithms for processing data obtained from the monitoring station are considered. This study was supported by the Ministry of Science and Higher Education of the Russian Federation.
The article presents an overview of the panoramic optical station "TomSky" developed at the Institute of Atmospheric Optics SB RAS, designed for day and night multiparametric observation of the optical state of the sky. In the first part, the prerequisites for creating a ground-based atmospheric monitoring station and some technical features of its implementation are considered. This study was supported by the Ministry of Science and Higher Education of the Russian Federation.
The article discusses the methods and algorithms used in the development of software and hardware systems for registration and analysis of cloud images, when observed from the surface of the Earth. The methods of pre-processing images are considered and the possibility of determining the direction and apparent angular velocity of cloud movement based on a series of images for the purpose of making a short-term forecast is evaluated.
Some features of the appearance of a mirror reflection of the illuminated underlying surface by a cloud layer consisting of ice plates from observations of a panoramic optical station are considered.
The work is devoted to the development of an algorithm describing the nature of the interaction of directed optical radiation with an optically transparent object of spherical shape – a raindrop. To solve this problem, in the approximation of geometric optics, the relations describing the angular nature of the radiation propagation in the droplet for four reflections from the interface of the two environments under consideration were obtained: air-water. Further, on this basis, the relations were obtained to describe the nature of the angular propagation of radiation outside the droplet for the four interaction points. As a result, the obtained relations were used to obtain digital data on the extreme values of the angles of the two functions: Ψ and φ . These values coincided with the angles of the primary and secondary rainbows formed by the interaction of directed optical radiation with a raindrop. Thus, the correctness of the developed algorithm describing the interaction of directed optical radiation with a raindrop is confirmed. This fact allows the estimation of the parameters of interaction of optical radiation with different values of refractive index, i.e., for other environments.
The article discusses various methods of image quality assessment. A comparative analysis of sharpness functions as a measure of image quality, in the absence of a standard for comparison, was conducted.
In this paper we consider the transformation of the trajectory of cloud formations in the system of the topocentric observer with their linear character of motion at a fixed altitude around the planet's surface.
The application of cluster analysis in the problem of classification of data obtained from remote sensing of the Earth is considered. A method for searching for image local features using masks Laws, and the formation of a vector of texture features is considered.
The paper presents the result of simultaneous observation of cirrus clouds by a lidar and an all-sky camera. The observation was started at 17:00, 24 March, 2016 and finished at 09:00, 25 March, 2016. The polarization lidar of V.E. Zuev Institute of Atmospheric Optics was used. The cirrus cloud was formed at 8000 m and went down to 4000 m at the end of observation. The linear depolarization ratio varied from 60% to less than 1%. The layer of quasi-horizontally oriented ice crystals was observed. Simultaneously, the all-sky camera pictured the 22 degrees halos while the lidar measured high depolarization ratio, which means that randomly oriented hexagonal ice particles were forming the cloud. The camera also pictured the Sundogs when the depolarization ratio tended to zero at about 21:30 that definitely indicates the quasi-horizontally oriented hexagonal plates. Absence of the Sundogs in the all-sky pictures while both the lidar sense low depolarization ratio, strong intensity and the specular reflection appears means that the cloud was formed by quasi-horizontally oriented particles with complex shape, i.e. snowflakes. The simultaneous lidar and all-sky camera observations seems to be a very prospective method to retrieve the microphysical properties of cirrus clouds.
We propose to determine experimentally the speed of the solar system relative to the selected inertial reference system. On the basis of parallel Lorentz transformation it is shown that for the path length ~ 30 km the diurnal and annual variations of the pulse delay time will have an amplitude ~ 0.24 μs. In accordance with the relativity principle, in any inertial reference frame (IRF) the speed of light is isotropic. We use herein a less stringent assertion: the only inertial system, S0, exists in which the speed of light is independent of direction; both the Earth and the Sun move relative to the system S0.
This report discusses some simulation results of the angular distribution of brightness of the sky in the case of molecular scattering in the atmosphere during the civil twilight with solar zenith angles 90 ° - 94 °.
This report discusses some simulation results of the angular distribution of brightness of the sky in the case of molecular scattering in the atmosphere for the benefit of the study of space-time changes of this distribution during the civil twilight.
The paper gives a short overview of methods of cloud detection and sky cloud cover level determination based on panoramic sky images obtained with the wide angle lenses of type «Fisheye».
This article gives a short overview to method of direction determining and visible angular velocity of movement determining of cloudiness based on set of panoramic images of cloudy sky, obtained by “Fisheye” wide-angle lens.
The results of floodlight sounding of atmospheric layers with spatio-oriented nonspherical particles are presented in this paper. It is shown that components obeying the regularities of diffuse scattering and specular reflection occur in the scattered radiation as a result of interaction of the directional optical radiation with such a layer. Depending on observational conditions, the intensity of specularly reflected component might be several times higher than the intensity of radiation diffusely scattered in the same direction.
The results of floodlight sounding of atmospheric layers with spatio-oriented nonspherical particles are represented in this paper. It is shown that components obeying the regularities of diffuse scattering
and specular reflection occur in the scattered radiation as a result of interaction of the directional optical radiation with such a layer. Depending on observational conditions the intensity of specularly reflected component may be several times higher than the intensity of radiation diffusely scattered in the same direction.
This paper describes an all-sky photometric complex being developed at the Institute of Atmospheric
Optics, Siberian Branch of the Russian Academy of Sciences, Tomsk. The complex is intended for the
observation of distribution of scattered solar radiation over the sky. Also given in this paper are description of an operating model of such an all-sky photometer and some preliminary results of
observations. The solar radiation scattered in the atmosphere is one of the important sources of information about the optical and physical state of the atmosphere.1 The development of means for observation of the atmospheric state based on recording of the solar radiation scattered in the atmosphere remains urgent now. Means for diagnostics of the optical and physical states of the atmosphere in real time on the basis of angular brightness distribution with allowance for the parameter variations as functions of elevation
angle and time are of special interest not only for scientific research, but also for meteorological and ecological applications.2 T1i is the objective to be pursued by the development of the all-sky
photometric complex.
The Planck law holds that brightness of a real thermal radiation source can be expressed in tenns of radiant emittance M(A,T) of absolutely black body (ABB) and function c(2) which establishes similarity of emitting properties between a real body and ABB. If in the spectral interval . the selective properties of the radiation source can be neglected, then the coefficient of body blackness c is often used in place of function c(A). During the past several years when the spacecraft measurements were carried out to investigate the Earth's natural resources the approach based on the assumption that each element of the underlying surface represents a secondary radiation source was employed1. If the selective properties of radiation of this source are neglected, then its spectral function of brightness can be represented as the Planck relation by replacing there the energy temperature T by the color temperature T. In the visible spectral range the Earth's atmosphere can be considered nonselective since several narrow water-vapor absorption lines and an ozone absorption line (Chappear) do not strongly affect its general form. In this case it is also possible to extend the approach used for investigating the natural resources to studying the Earth's atmosphere. In our paper we discuss some calculational results of determining T and c of the solar radiation brightness field scattered in the atmosphere.
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